Rod, he's getting a 1/32" thick magnet, I'm sure Dallee doesn't have anything smaller. I venture to say, they probably get their magnets from a place like K&J Magnetics. The bonus is K&J will be MUCH cheaper than Dallee for the magnets!
The magnets Dallee sell with their reed switch are: 0.2 Inches x 0.12 Inches X 0.05 Inches, $15 with a reed switch.
K&J has ten of them for $1.10, 1/8" in diameter and .032" in thickness.